Harmonic electric bell or ringer.



C. J. ERICKSON. RMoNIc BLECTRIG BELL 0R RINGER.

A'YPLICATION FILED DEO. 18, 1905.

Patented May 13, 1913.

' electric bell embodying the principles of my UNITED ,sTArns rTENT OFFICE.

CHARLES J. ERICKSON, 0F CHICAGO, ILLINOIS, ASSIGNOB, BY MESNE ASSIGNMENTS, TO FIRST TRUST AND SAVINGS BANK, TRUSTEE, OF CHICAGO, ILLINOIS.

HARMONIC ELECTRIC BELL OR RINGER.

Speeication of Letters Patent.

Patented May 13, 1913.

To all whom it may concern Be it known that I, "CHARLES J. EmoKsoN, a citizen of the United States of Amerlca, and resident of Chicago, Cook county, Ill1- nois, have invented a certain new and useful Improvement in Harmonic Electric Bellsor Ringers, of .which the following 1s a specification.

My invention relates to harmonic ringers in general, but more particularly to harmonic rin ers of the polarized type, such, for examp e, as the ringers or electric bells employed in selective ringing party-line systems. Ina telephone system it has been found to be of great advantage for the operator to be able to ring any bellon a partyline without ringing the bells of the other subscribers on the same line; for with thls arrangement, it is not necessary to use a dif ferent number of rings for each subscriber. Consequently, in a selective ringing system, and regardless of the numberof sulbscrlbers on any one line, only the bell of the called subscriber will ring.

Generally stated, the object of my invention is the provision of an improved and hi hly eiiicient harmonic ringer for use in seective signaling systems.

Special objects of my invention are the provision of im roved means for adjusting the ringer to di erent frequencies or periods of vibration; the provision of improved means for mounting the striker andA armature of a harmonic ringer; the provision of an im roved construction and arrangement whereby the yoke of a polarized electric ringer can be made to serve as the flexible ree or tongue for the tuned striker; and the provision of certain details and features of improvement tending to increase the general efficiency and serviceability of a ringer or electric bell of this particular character.

To the foregoing and other useful ends, my invention consists in matters hereinafter set forth and claimed.

In the accompanying drawings, Figure 1 is a front elevation of a harmonic ringer or invention. Fig. 2 is a detail sectional view of the lower end of one of the electro-mag nets and adjacent parts. Fig. 3 is a detail perspective of one of the posts or mountings for the gongs. Fig. 4.- is a detail sectional view of the bracket-plate and the connection between the same and the upper end of the permanent magnet. Fig. 5 is a plan view of the combined yoke and spring or reed upon which the striker is mounted.

As thus illustrated, my invention comprises a frame or bracket-plate A and two electro-magnets B and C secured thereto by the screws 1 and 2. The said frame or bracket-plate is provided with two upwardly-extending arms 3 and 4 which are bent into positions parallel with the coils of the electro-magnets, but which extend upwardly instead of downwardl, The end portions of the said arms 3 an 4 are then bent at right angles, thus forming end sections to which the gongs D and E are secured. As shown in Fig. 3, the angle section 5 is very clearly shown, which sec- -tion is provided with an opening 6 through which the bell screw 7 passes, said screw being locked in place by a nut 8 on the under side of the section 5. The arms 3 and 4 are, furthermore, arran ed at a suitable distance apart in order t at the gongs D and E may be adjusted to receive a striker 9 between them. Said striker may, of course, be of any suitable shape; but as shown in Fig. 1, the said ,striker is cylindrical and secured by a screw 10 to the striker-rod l1. In this way, the striker 9 can be adjusted along the length of said rod, according to requirements and with a view to adjusting the bell or ringer to different frequencies or periods of vibration. As illustrated, the pole-pieces of the magnets B and C have a strip F secured thereto, said strip being of thin iiexible and nonmagnetic material, and secured in place by means of the holes 12 and 13. Screws 14 and 15 are inserted through these holes and serve .to hold Athe said combined yoke and spring-mounting in place.` With this .ar-

. rangement, it will be seen that the member F constitutes the yoke for connecting the cores of the two electro-magnets. Furthermore, and between the said clamping sections, the said spring F is provided with a second opening 16 which receives the thread ed end portion 17 of the striker-rod 1-1. 'To the spring-plate F the said rod 1s clamped by a nut 18 and a shoulder 19, the same b eing arranged on opposite sides of the said springy member F, whereby the latter constitutes the sole means for supporting the striker and its rod. Near the extreme threaded end of the threaded section 17 the armature G is clamped between the nuts 20 and 21, and may be adjusted thereon with respect to the pole-pieces of the electromagnets B and C, by the adjustment or movements of said nuts. It will be seen that the nut 2O is in the nature of a thumbnut and can be rotated or adjusted without the aid of a tool. Again, and from the under part of the frame or bracket-plate A, a flange 22 extends toward the front thereof, and carries on each side of its end a lug 23. To this flange the permanent magnet H is secured by a screw 24. With this arrangement, the said magnet H extends below the electro-magnets B vand C, and be ond the lat-ter, and with its end 25 arrange in close proximity to the lower threaded end portion 17.

' Referring to Fig. 2, it will be seen that the screw 14, the head of which is hexagonal, is fvung into the core 26, the latter being threaded. When the striker-rod 11 is in normal position it extends through the opening 27 in the frame A; and in this opening said striker-rod vibrates when a current of suitable frequency passes, through the electro-magnets B and C. It'is obvious that the striker-rod is able to vibrate, since the thin and springy and resilient yoke F is' iiexible enough to permit the tilting'of the armature Grl when acted f upon by the electro-magnets B and C.

With the foregoing arrangement, it is obvious thatthe bell or ringer may be so adjusted as to respond to different frequencies or periods of vibration.

The spring F can be tuned to respond to any desired frequency. In other Words, the spring of one bell or ringer can be of a -certain gage or weight or flexibility, so as to-be responsive to one frequency of current, and the springs of the other ringers on the same party line can then each be of a different gage or weight or flexibility, thus making them responsive to different frequencies of current. With this arrangement each striker or striker-rod is secured to a spring, and each striker-rod and its striker is adapted to swing abo-ut an axis at its point of connect-ion with the spring. Preferably, as illustrated, the striker-rod extends at right an gles to the spring. and the spring is preferably straight and secured at each end.

lVhat I claim asmy invention is 1. In a bell or ringer, gongs, electro-magnets, a permanent magnet, a spring yoke of sheet-.metal connecting the ends of'said electro-magnets, a striker rigidly secured to the middle portion of said yoke, the striker being entirely free except where connected with said spring, and an armature rigidly connected with said striker and arranged between the permanent magnet' and the ends of the electro-magnets.

2. In a bell or ringer, electro-magnets, a"

leaf spring yoke connecting the ends of said magnets, a striker-rod secured to the middle portion of said spring yoke, an armature for operating said striker-rod, a striker adjustably mounted upon said rod, the striker being entirely free except where .connected with said spring yoke, and sound-producing means adapted to be engaged by said striker.

3. In an electric bell or ringer, a thin` resilient spring member, suitable means for supporting said member, a rod secured at right angles to and supported by said thin resilient member, an armature rigidly secured to said rod, the said member and armature being disposed in. parallel planes,

lfree or swinging end of said rod, electromagnetic means' for operating said armature, sound producing means to be engaged by said striker, means for permitting adjustment of the striker on the rod, and means for permitting adjustment of the armature on the rod, said thin resilient member disposed bet-Ween the 'iarmature and the striker.

5. In a bell or ringer,- an electromagnet, a

spring mounted at its opposite ends, a'

striker mounted upon the middle portion of said spring, an armature for operating the striker, said spring and armature being disposed in parallel planes, the armature being magnetically propelled in both directions to reverse the tension of the spring by which it is carried, which. springnormally holds the armature at the center of its vibratory movement, and sound-producing means adapted to be engaged by said striker.

6. In a bell or ringer, a sprin' mounted at ifo its opposite ends, a striker rigi 1y secured to I an intermediate portion of said spring, an armature rigidly connected with said striker,

electromagnetic means for operating said armature,'said springl and armature being Signed by me at Chica o, Cook county, disposed in parallel planes, the armature Illinois, this 2nd day of ovember, 190.5.v 10

b'emg magnetlcally propelled in both directlons to reverse the tension of the spring by CHARLES J. ERICKSON. 5 which it is carried, which spring normally holds thev armature at the center of its 'vi- Witnesses bratrory movement, and sound-producing r Enw. D. FALEs,l

means adapted to be engaged by sald striker. JoHN- ERICKSON.

copies of this patent may be obtained for ve cents each, by addressing the commissioner o! Patents.

Washington, D. C. 4 

